The effect of deep neck flexor endurance on craniovertebral angle changes and neck and shoulder muscle activities...

The deep neck flexors are important for maintaining neck posture by stabilizing and supporting it through low-intensity contraction, ensuring static endurance. The subjects performed computer tasks after having their deep neck flexor endurance measured using a pressure biofeedback unit. The craniovertebral angle (CVA) and the muscle activities were measured while participants were completing computer tasks for 10 min. The deep neck flexor endurance was significantly negatively correlated with CVA changes at 0-2 min. The deep neck flexor endurance was significantly negatively correlated with sternocleidomastoid muscle and upper trapezius activity at 0-2 min. The deep neck flexor endurance negatively predicted CVA changes at 0-2 min and explained 28.8% of the variance in the CVA changes. The lower the deep neck flexor endurance, the earlier the simultaneous changes occurred in the CVA and the neck and shoulder muscle activities during computer tasks.